Power transmission belt



Feb. 8, 1949. A I`:. A. MILLER POWER TRANSMISSION BELT Filed June 27, 1944 EDWIN ALIGLIET MILLER MMT AT Ty Patented Feb. 8, k1949 "This inventiony relates .to power transmission tion is to provide.meansfadaptedfeto compensate for the usual side expansion ofthat type of belt in itstlexed relation to vaepdlleyfwheel asitpasses 'f ALtlrerearound.

:Another y:object Wis Ato-i-provide `@such 'control oi. side expansion that the belt may ride the pulley wheel in a Xed circumferential path to thus maintain a steady rate of speed throughout the entire belt.

A further object is to provide the belt with crosssectional co-operating means adapted to maintain the pulley Wheel contacting surface of the belt in an evenly exed pressure.

With reference to the accompanying drawing, Figure l is a perspective cross-section of a fragmentary portion of the improved belt; Figure 2 is a cross-sectional view of said bel-t, one of the co-operating means in contracted condition; Figure 3 is a reduced side View of a exed portion of the belt, one rim of the pulley wheel being omitted to expose the exed portion; and Figure 4 is a cross-sectional view of a slightly modified belt.

With more particular attention to the accompanying drawing, the numeral I designates the outer covering of the belt, the meetingedges of which are cemented, or otherwise relatively secured one to the other, by the adhesive 2. The upper and lower parts 3 and 4, respectively, of the covering I are substantially parallel, one to the other, and the outer side-surfaces?, and 6 are relatively convergent with relation to the upper part 3, the covering I thus assuming a cross-section of trapezoidal form. Each of the side-surfaces and 6 is integrally provided with the external, relatively spaced and outstanding ribs 1, said ribs 'I each having a flat contacting surface I throughout its length. Between each of the ribs 1 is an elongated recess I' of which the sidesurfaces 5 and G provide bases therefor.

Vertically positioned with relation to the belt interior are one or more blocked-shaped strips 8 extending continuously, or in'sections,.thefentire belt structure, said strips 8 comprising some form of flexible material, such as rubber. 'Between' such strips 8 and the inner side surfaces of said covering I there is inserted or positioned a suitable packing I I filling the compartments 9 and lil thus established as when a single-strip 8 is centrally positioned as illustrated bylthe Figure 1, said packing II being of fluid character?? Either one or the other of the `fl`exib e' strip 8 or the outstanding ribs l, may bejo'm'itted in the 2 claims. (amie-Lees) ,2 zconstructionnFthe 'improved belt, if desired, but w ereboiihffare-Hincluded 4they together provide eco VVope'fratingfaiciltiesi'for fully counteracting the lorlcl'nary2fieiredfcondition of the V-type belt.

fflrroperation, 'where the fully improved "belt is installed, forinstance,connecting a power pulley avheelILZ"andlftransmitting power thereby to an auxiliary pulley wheel, not illustrated, some portion of the belt is always in flexed condition as the belt passes over either wheel, as illustrated by the Figure 3with relation to the wheel I2, thus `maintaining the outer convergent side-surfaces 5 and 6, adjacent the upper part 3 in a normal nat condition, whilethe lower outer sidesurfaces 5 and 6', carried by the lower part 4, becomes puckered, thus cramping adjacent portions of the packing II within the covering I, which packing II thereby forced in directions of the least'resistance, namely against the eXible strip 3 and the recesses I', both of which yield to such force, as illustrated by the Figure 2 with relation to the flexible strip 8. The yielding ofv such force at the recesses I causes an expansion outwardly thereat, but not exceeding beyond the projection of the ribs 'I so that the outer face 'I' of the ribs 1 maintains an unchanged even pressure-contact with the V-walled surface of the rim I2 of the wheel I?. throughout its passage over the wheel I2. This is true with regard to the lower side-surfaces 5 and 6 even though the flexible strip 8 is omitted in the construction of lthe improved belt, although with greater stress upon the recessed portions. are omitted in the construction of the improved belt, the flexed force seeks the course of the least resistance, the strip 8 yielding as such force is communicated through the flexible packing II,

while the contacting portions of the outer side-y surfaces 5 and 6 maintain a steady frictional grip upon the V-walled surface'of the rim I2 of the Wheel I2.

The Figure 4 illustrates a slight modication in which the vertical flexible strip 8 extends longitudinally between companion parts of the belt structure, thereby establishing two compartments 9' and I0', each having its covering I This modiiication is illustrated as being prof Where the ribs y'I' 3 vided with outstanding ribs 1", as in the preferred form, but such ribs 1 may be omitted if desired.

The operation of the modified form of belt is substantially identical with that of the preferred form, the iiexible strip 8 being adapted to yield laterally to external pressure displacing the lower portions of the convergent sides and also the packing upon a flexed condition of said belt.

1. A power transmission belt of V-type comprising a top portion extending throughout the length of the belt and dening the outer circuml ference of a flexed belt portion; a baseV belt portion of lesser Width than that of the top portion and dening the inner circumference of saidV f Y flexed belt portion; converging side portions connecting said top and base portions; a exible 4 combination of a exible member of block rubber, or the like, centrally connecting the top and base portions of a belt and having upon either side thereof a suitable iiuid material Within converging sides of said belt; and spaced outstanding ribs with which said converging sides are exterlorly provided, said flexible member and said ribs being adapted to co-operate in resisting lateral pressure contact of a iiexed belt. Y

i f r' l-EDWINv AUGUST. MILLER.

REFERENCES CITED n The following references are of record in the member of block rubber, or the like, centrally connecting said top and base portions; and a suitable iiuid material between said block rubber member and said top and converging side portions, the slight lateral yielding of said nuid material, the particles of which move Without separating the mass, is substantially resisted by said centrally positioned flexible member.

2. A power transmission belt of V-type, the

UNITED STATES PATENTS 230,219 Y ,Great Britain Mar. 12, 1925 

